Hi,
didn't find a solution for my problem via google or the forums search on how to use tha Avatar Add-On (
http://modx.com/extras/package/avatar).
As I'm not that experienced with PHP I don't understand how to use the upload Snippet [[avatar.upload]]. Simply calling it within a Chunk or a Template didn't do anything. Unlike other Add-Ons like Login you don't have the chance to define a chunk with some HTML forms.
In other words: I just don't know you to use it.
Best,
Daniel
